1. The Field of the Invention
This invention relates to a combination faucet and antisyphon break fixture for use with a small reverse osmosis system producing purified water for household use.
2. The Prior Art
Small water purification systems employing a desalination unit operating by reverse osmosis and designed to produce a few gallons of water a day for household use, often hold purified water in a pressurized storage tank and dispense this water as required through a suitable faucet. Such reverse osmosis purification units, however, also produce a flow of waste by-product water or brine, which is high in salt content and is disposed of through connection to a sewer system.
In order to dispose of the brine, laws and ordinances often require that such sewer connection be provided with an adequate antisyphon break or air gap that will positively prevent the possibility of sewage being syphoned back into the reverse osmosis brine connection and thus to the water line leading to the reverse osmosis unit, and to the water supply being purified. An air gap of at least one inch in the drain line, and at a specified height, is a common requirement, and suitable air gap fixtures are available for mounting on a sink or drain board, usually spaced apart from the faucet that supplies purified water.
To avoid the expense and inconvience of a separate air gap fixture, faucets of a type suitable for the purpose may be provided with an integral air gap as described in U.S. Pat. No. 3,620,241, issued Nov. 16, 1971. Such combination faucet and air gap fixtures operate effectively when first installed, but after a period of use may require frequent servicing, repair and sometimes replacement, caused principally by the corrosive nature of the brine flowing through the brine ducts and air gap system. Contact of the highly saline brine with any metal surfaces in the faucet fixture has resulted in corrosion and erosion of such surfaces, and formation of a hard deposit or crust of salts and corrosion products which at times can partly or even wholly obstruct brine flow passages, and may even affect the functioning of the air gap itself.
A combination faucet and antisyphon break or air gap fixture which would be immune from brine corrosion effects would be a substantial improvement.